Antenna



March 10, 1953 .1. w. SHERIFF ANTENNA Filed Oct. 20, 1950 Pie. 1

INVENTOR Y JACK W. SHERIFF ATTORNEY Patented Mar. 10, 1 953 UNITED STATANTENNA Jack Wavelyn Sheriff, Oak Lawn, Ill.

Application October 20, 1950, Serial No. 191,256

My invention relates to antennas, as used in radio and television andrelated fields. An object of my invention is to provide a structure forthe radiation or reception of radio frequency energy which will havehigh gain, highly directional characteristics including highfront-toback ratio, and which will exhibit these characteristics inmarked degree over an extended range of frequencies.

'An antenna having these features is particularly useful for receptionin the bands presently assigned for television, where the ratio offrequencies at the extremes of the range is about 4 to l. Antennas nowcommercially available at reasonable cost do not have satisfactorycharacteristics over such a wide frequency range. My invention provides,in a structure which can be manufactured at moderate cost, a highlydesirable efficiency over all the television bands, 55 megacycles to 216megacycles. The principle of my invention, of course, can be applied inother circumstances where it is desirable to have an antenna with highgain over a wide frequency range.

In the accompanying drawings,

Fig. 1 represents a plan View of one embodiment of my invention, and

Fig. 2 represents a plan view of another form of my invention.

The structure shown in my drawings can be readily fabricated fromaluminum or other light weight metal tubing, as is presently common inthe art. The elements may, however, be made of any form of materialhaving satisfactory conductivity at the frequencies involved, togetherwith the necessary mechanical qualities of strength and rigidity.

In the drawings I have used the reference numeral Hi to indicate thelongest element of the structure. It is connected to, and in the usualcase supported by, a pair of elements designated as [2 and [2a. Thesethree elements are arranged in triangular configuration, as the drawingshows. The converging ends of the elements I2 and 12a are mounted on andelectrically insulated from each other by an insulating block I4.

A pair of elements l6 and "a are connected respectively to the adjacentends of the elements [2 and I2a, and extend outwardly in axialalignment, substantially parallel to element I0. Another pair ofelements, I8 and i811. are connected respectively to the outer ends ofelements l6 and l6a, in triangular configuration as shown.

6 Claims. (01. 250-33) Energy is fed to or from the antenna by a feederor transmission line of conventional twoconductor type, indicated at 20.Connection for this purpose is made at the junctions of elements 12 andI6, and of elements [2a and Ilia. .The

ment In is made to be /2 wave length for a slightly higher frequency B.Elements l8 and l8a are each /2 wave length for a still higher frequency0, and elements l6 and Ilia are each A: wave length for a frequency Dnear the high frequency end of the desired range.

The elements i2 and 12a may be connected to element In at the ends ofthe latter, or at pointsspaced inwardly somewhat from the ends, as shownin the drawing. In the television bands, I find that the latterarrangement gives an increase in gain.

. The direction indicated by the arrowin the figures is the one in whichthe antenna radiates the maximum signal, when used for transmitting,

or from which it has the greatest gain, when used for receiving. Theside of the system on which the arrow appears is usually referred to asthe fron of the antenna, and I refer to the large triangle consisting ofthe elements l0,

l2 and 12a as the front structure, and the balance of the system as therear or back structure. Normally the two triangles lie in the sameplane, and the block [4 is mounted on a vertical mast (not shown) aboutwhich the system can be rotated to give the desired directionalorientation.

My invention can be embodied in another form which I have illustrated inFig. 2. In this form the front structure is substantially the same asthat in Fig. 1, and I have used corresponding reference numerals, H0referring to the longest element, H2 and H211 referring to the sidemembers of the triangle. In the rear structure, the element H6 isarranged parallel to H0, and is connected to and supported by thediverging ends of elements H8 and 8a. The apex or converging ends of H8and H811. are connected respectively to the corresponding ends of H2 and2a, and the transmission line I20 is connected to the system at thesejunction points.

In either embodiment of my invention, the frequencies A, B, C and D canbe selected so that they will be spaced across the desired range ofoperation at intervals to give relatively high gain throughout therange, and/ or they may be chosen to place the resonances at points inthe range where particularly eflective functioning is required. Thecorresponding lengths of the various elements of the antenna, aspreviously indicated, will thus be determined. Y

In the claims, for simplicity; I use the termfed, or similarterminology, to indicate the connection of a line by which energy isbrought. to or taken from the antenna system, but it will be understoodthat this is not intended to limit the application of the structuredefined to..either receiving or transmitting use.v

It will be understood that some changes may be made in the constructionand arrangement:

substantially an isosceles triangle, the electrical continuity ofthe.triangular; configuration being interrupted byalgapzinethe base elementof said-- triangle on the line of symmetry of. the cone figuration,three additional elements in'the configuration of an isoscelesitriangle,the isosceles; sides being separated; at their. converging ends; andsaidconverging ends being connectedree spectively to elements of saidplurality on; op.-

posite-sides of said gap,-said system beingfed at said gap.

2; An antenna system comprising: a settofi rectilinear conductiveelements in triangular'conq, figuration, arrangedto be connected to atransmission lineat one corner of the triangle, and a.

second set of' rectilinear conductive elements in triangularconfiguration, arranged to form an.

electrically discontinuousgap at the midpointiof one side of theconfiguration, and to be connected to the same transmission line at saidgap.

3'; An antenna system comprising a set of rectilinearconductive-elementsin triangular con figuration; arranged to beconnected to a trans-. mission line atone-cornerof the-triangleand asecond set: of'rectilinear conductive elements ar ranged to formatriangle substantially smaller in sizethan. said first mentionedtriangle, but

' '4 lying in the same plane therewith, and connected to the sametransmission line at the midpoint of one of the elements of said secondset.

4. An antenna system comprising a group of elements in triangularconfiguration, joined by a transmission line at one corner, and a secondgroup of elements arranged in triangular configuration having one sideparallel to the side of said first triangular group opposite the linecorner thereof, the element forming said one side beingjoined'atitsmidpointto said transmission line.

' 5. An antenna system comprising a front and aback structure, saidfront structure comprising an isosceles triangle fed from the apex ofthe isosceles sides,1and said back structure comprising a, triangle fedfrom the center of one side,

' said one side being substantially parallel to the side'of said frontstructure opposite the apex thereof.

,6. An. antenna, system comprising a, front structure and a.rearjstructure, Said front structureconsisting ofjtwolelementsarranged'in \l' relation and. a third element connected" acrossthetopsof the. V, said two elementsv being in sulated, from each,othertatthe apex.v of. the. V,

saidrear structure. consisting of four elements,

twov of said four elements being, supported in,

tively; at their'inner; ends to the, apex, ends. of

said first-two elements of said frontstructure,

said system beingfed at said last mentionedpoints.

of connection. JACK WAVELYN. SHERIFF.

REFERENCES CITED The following references-are of record: in the file of;this patent:

v UNITED STATES PATENTS Number Name Date 2;017 ,12l, Gouriand Oct.15,1935 2 ;4 52, 1 06, Cotchefer; Oct. 26., 1948.. 2,471,215 Jackson.,.a May, 24,1941" 2,559,149 Ercolino. July '3, 19511

